Jack Draper suffered from cramp during his loss to Nadal in Melbourne (Picture: Shutterstock)

Jack Draper insists he needs more time to make himself physically strong enough to compete at the highest level after being struck down by cramp during a four-set loss to Rafael Nadal in Melbourne.

The draw had given the 21-year-old rising British star a blockbuster clash with his idol on his debut at the Australian Open against the defending champion, who has endured a run of poor form.

Draper looked capable of causing the upset when he took the second set on Rod Laver Arena but physical struggles have hampered his career so far and he began to cramp in the third set before hobbling through the final stages as he went down 7-5, 2-6, 6-4, 6-1

World No.38 Draper admitted his preparation had been far from ideal, saying: ‘Going to this trip in Australia, I was very undercooked.

‘After last year, I was excited about doing a good pre-season. I had two viral infections so had to be on antibiotics on two occasions. I lost five of those seven weeks.’

Draper, who reached the semi-finals of a warm-up ATP tour event last week before a gruelling defeat to Soon-Woo Kwon, said: ‘I’ve got to be proud of the way I competed in Adelaide. I surprised myself with where I’ve been at.

Rafael Nadal plays a backhand (Picture: Andy Cheung/Getty)

‘Obviously this physical thing is going to take time. It’s going to take patience. But I’m fully aware of that and willing to do everything I can to put myself in a great place. Physically, I’ll be the first to say I’m still a work in progress.’

Draper, who recently hired a fitness coach in Croatian Dejan Vojnovic, added: ‘I felt at the beginning of the third that my tennis was right there. I almost felt like I was in control of the match at that point.

‘The first set’s always tough. I’ve never been on court with Rafa before. The second set, I sort of calmed down and started playing really well. If I would have carried on that way, who knows?

‘I just need to investigate why I’m getting (cramp) but also know that I’ve only just started really with my fitness trainer that I’ve invested in.

Draper leaves Rod Laver Arena after losing to Nadal (Picture: Stringer/Anadolu Agency via Getty)

‘Obviously playing a player like Rafa on Rod Laver, something that I’ll remember for a very long time. A real honour to play against him, someone I’ve idolised growing up.

‘To go toe-to-toe with him on a big court like that is special. I think I can take away the fact that my tennis is getting closer and closer.’

The British No.3 was praised by Nadal who said: ‘I played one of the toughest possible opponents in the first round. He is young, he has power and has a great future.’

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Nadal, who made 46 unforced errors against Draper, added: ‘I need a victory, so that’s the main thing. It doesn’t matter the way. We knew it was not going to be perfect, as I said the other day. It was not perfect.

‘But to win against Jack, I need to do things well. I think I did things well. So I’m satisfied with the victory because that gives me the chance to play after tomorrow again.’

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‘The first set’s always tough.’